Fiber Optic Glass (Cat's Eye Glass)
Synthetic Borosilicate Glass var. Fiber Optic · Decorative Stone / Synthetic Gemstone
Crystal System
Amorphous (Non-crystalline)
Mineral Group
Man-made Glass / Silicate Composite
Chemical Formula
SiO2 with B2O3, Na2O, and various metal oxide colorants
Formation Process
Synthetic melting and drawing of glass fibers fused into rods and cut into cabochons or beads
About This Crystal
The beads display a vibrant array of artificial colors including pink, blue, yellow, dark blue, green, light purple, orange, and black. They are translucent to opaque with a vitreous to silky luster, featuring a distinct centralized line of bright light (chatoyancy) due to parallel fiber alignment.
Physical Characteristics
Varies by dye, white streak, no cleavage, conchoidal fracture, specific gravity around 2.5, brittle tenacity, inert to magnetism and UV fluorescence
Optical Properties
Singly refractive, isotropic glass with a strong chatoyant effect (cat's eye effect) caused by the parallel optical glass fibers
Hardness & Durability
Origin Region
Manufactured primarily in factories in China and India
Hardness & Durability
Mohs hardness of 5.5 to 6, fair toughness, stable against normal light and heat, but sensitive to hydrofluoric acid and strong impacts
Care & Maintenance
Clean with warm soapy water and a soft cloth, avoid ultrasonic cleaners and harsh chemicals, store separately to prevent scratching
Rarity & Value
Common, very inexpensive, mass-produced decorative material with no natural scarcity value
Special Characteristics
Exhibits intense chatoyancy (cat's eye effect) due to thousands of microscopic glass fibers acting as light guides
Lore & History
Often marketed under trade names like 'Fiber Eye' or 'Cat's Eye Opal' for crystal healing, associated with intuition and protection, though strictly a modern man-made novelty material with no historical mineralogical significance